Driving-belt.



M, LEBLANC.

DRIVING BELT.

APPLICATION FILED DEC.H. L9L2.

l ,265,363. Patented Non 21, 3916..

L/ l l Y I UmransTATEs Farm onirica,

MAURICE LEBLANC, or VAI. son' snrrm 'PAR cnors, FRANCE, assrsnoa To socinfr .ANONYME roca LExPLorrarroN Das rnocr'uias wEs'rINGHoUsn-LEBLANC, or

PARIS, FRANCE.

DRIVING-BELT.

Specification of Letters Patent.

Patented Nov. 21, 1915.

- Application led December 11, 1912.' Serial No. 736,092.

To all whom it may concern: v v

Be it known that I, MAURICE LEBLANC, a citizen of the Republic of France, residing in Val Sur Seine par Croisy, (Seine et Oise,) France, have invented certain new and useful Improvements in vDriving-Belts, of which the following is a specification.

This invention relates to a new type of driving'belt made of vegetable or animal fibers, and comprises a foundation formed of parallel threads placed side by side and glued to one or two' bandsof thin cloth, the Whole being covered by a protective fabric of a knitted kind which is first dressed and then glued to the said cloth. The protective fabric should be wider than the layer of threads to avoid damage of the belt when this is used under conditions which subject it to lateral wear, and the fabric should be reinforced by being thickened at the edges so as to be better able to resist the destructive action of the belt fork.

The following description with reference to the accompanying drawing will serve to explain the invention.

Figure l is a transversesection through a driving belt, in which there are two bands of cloth. Fig. 2 shows a modification of Fig. l.

Figs. 3 and 4t are diagrammatic elevations of two forms of apparatus suitable for manufacture of the belt.

The belt consists of a layer of threads (1,;

4placed side by side and parallel to each other, the layer being glued to an upper band and a lower band b of thin cloth ini* threads is to give the belt the desired resistance to traction. Since the threads subjected to the pull are straight and all under equal tension, they operate simultaneously and as they are embedded in gelatin or some other suitable agglutinant, the elongation lwhich they suffer under the tension required of the belt is a real elongation of the ber of which they consist, so that the belts of which the threads form a part are not subjects-d to any preliminary elongation, as is the case with cloth belts which are required to resisttractionand wherein the sinusoidal `curves formed b the chain threads must be rectied before the threads themselves are stretched. The band of high resistance thus formed is covered by a protective fabric c analogous to that produced bylace making machines, or rather by knitting machines. This fabric is dressed, glued to the band and subsequently covered by 'a Waterproofing coating. This fabric protects the band from damp and from wear -by friction; it'also gives the belt the best possible adhesion.

An important function of a fabric having a Warp 1s that it allows the use of the fasteners usually lused for connecting together the ends of a driving belt. For this purpose the warp Should be sufficiently' strong, for it will have to support the shear- 1 ing action produced by nearly all types of fasteners which do not act bv pressure.

It has already been stated that the protective fabric should have high resistance to friction and in particular the friction due to the belt fork, and foi` this purpose the invention provides a fabric, slightly Wider than the band of parallel threads,

and thick portions d consisting-ofy pads "of fabric, as shown in Figs. 1 and 2.

In the vfollowing there are described by way of example two processes formanufacturing belts according to this invention, eitherin long lengths which can be cut'up into belts of the desired length, orin the form of endless belts of an exactly pre-determined length suitable for the driving.

The chief advantages'presented by the belts made according to the invention are as follows :-1. That they have the property which has been improperly called inextensibility, and is in reality theproperty of remainingt stretched onl the pulleys without the necessity for shortening the belts several times, as is the case with leather belts and' woven belts. 2. That they have little thickness owing to the fact that they con# sist of only a single 'layer ofthreads contained between two layers of fabric. 3. They are light in comparison with their resistance to traction, so that they can vtravel at high .linear speeds, namely up to 70-80' meters per second. 4. They, are supple ow-l ing to the fact that there is only a-jsingle layer of rectilinear threads, while the protective fabric, being woven, possesses a power of elongation much higher than that of the ,intermediate layer andcnly opposes los the. smaller eurrntures of the belt when these become exaggerated and would entail breakage.

No belt manufactured hitherto displays the characteristics which are obtained principally by the adoption of a single layer of threads, thus permitting the utilization of powerful agglutinants, such as gelatin, which do not .impart stillness, both for the lay r itself and for the protective. covering. A. knitted fabric is more especially suitable for this protective covering. because such fabric dees not possess threads comparable lwith the chain threads of a ivoren belt, and in consequence 'wear due to friction and particularly the wear produced by the belt fork, does not give rise to fraying. as in the case of Woven belts. rl`he coveringfebric niay have a Warp so that the belt may be made without the. cloth band already described, and the threads of this Warp are connected by of knitting which prevent the belt from breaking.

Fig. 3 represents tivo drains A, B, facing each other on which is Wound a thread of istance. suitable for the force which the belt has to transmit. it is obvious that the thread may be `wound on the drums through a number of turns as may be necessary, a colnb K movable tranrversely beine; used to prevent the thread from crossing itself. A. constant tension given to the thread by any suitable means, such as by a Weight P on a small pulley. When there is a number of turns suitable for the width of the belt desired., the several turns are pushed close to each other by hand and they are covered with a solution of glue or other suitable agglutinant. lf a cloth band is used this is nou' `glued to the layer of threads on one or both faces thereof. lllhen the band'is to be applied to both faces it is conveniei'it to use a baud of a little more than twice the Width of the layer of threads and to apply it so that it extends equally beyond the sides of the layer and is then foldedover the layer, its overlapping edge being glued so that the layer of threads is entirely surrounded by the band. The `protective fabric which has already been dressed is now glued to the two faces of the band. The fabric is dressed and the sticking operations already described are performed .i n different agglutinants; for instance the threads are glued with gelatin and the knitted protective. fabric is coated with carniti'houc. The .Whole is now allowed to diy x. v be cut up to forni belts of desir-ed lengths.

lf the distance between the drums A and B is such as to produce a belt of a desired length, the belt can be made iiithoiit being cut. ln this case since the protective fabric will be supplied in the forni of very long,T bands, they inay be cut to the desired length and the ends connected together by carefully Lenssen splicing, so that the excessive thickness of the junctions may be negligible.

When long lengths are to be ina-de to be subsequently cut up into the desired lengths, the gluing operation may advantageously be performed in tivo stages. The layer of threads glued to a cloth band or not may be allosved to dry and wound upon a drinn. lllhen a band of cloth is not used, this opel`- ation only possible if the agglutinant has sullicient resistance, as is the case with caoutchouc or glue. Then, shown in Fig. '-l, the drinn gy, carrying.;` the layer of threads, is mounted between two other drums f, L, cach carrying' a band of protective fabric previously dressed; the three bands are now uni-oiled from their respective rollers, passed through an opening` z' u' lere they are broughttog'ether, and inally into vat f: containing hot glue. Long lengths may thus be glued Very easily. Electors for throwing; on the glue can. further be provided before the slot i between the bands of protective fabric and the band of parallel threads.

For producing theV knitted protective fabi ric, the frames known in the trade as Rachel frames may be used. rlhese frames Coniprise principally tivo bars each Carrying a. row of needles which are caused to rise and descend alternately one after the other, While the threads are Conducted and turned around the needles by heddle hooks mounted on the bars and operated by a suitable Iilovew nient. These frames permit of a Warp thread being introduced in the knitting. .lt is placed between the needles and the threads before the latter Wind themselves around the needles and when the needles descend to make the mesh the Warp thread is taken, in. n

Generally' the frame will be operated With a single row of needles so that the fabric may?l ave little thickness; it suffices there foie suppress the needles of the other row. However, in certiin ceses of belts Which have to Work under Very unfavorable conditions the knittinglniay be used which is made on both rowsmof needles, that is to say presenting two roytsj of mesh in the thicknessgrsuch a fabric "may be provided with one or two Warp threads for the double row or" meshes. Generally the layer of parallel threads is glued between two knitted fabrics as aforesaid, and care is taken that the layer of glue should be as thin as possible so as not 'to make the belt stiff.

To protect the edges on the belt against the destructive action of the belt fork or any other source of friction, if knitted bands made upon a single row of needles and therefore haring only a single thickness .of mesh are used, there may be applied as already stated to each side of the band protective pads of the thickness of one or several meshes, which are produced by knitting these sides on both rows of needles. These edges will therefore have a double thickness of mesh and may be made with coarser threads. It will also be apparent to those skilledin the art that these edges may have placed in them longitudinal threads which are not meshed but are simply surrounded by the mass of the..fabric for the purpose of Y imparting a certain stiiness to these protectivefedges. When the fabric .is to have a double row of meshes the edges can be reinforced by using for makingthem coarser and more compact threads than those used for the .middle part of the band. With frames specially constructed for this purpose the warped fabric could be formed directly around the layer of parallel threads which would be stretched between the two rows of needles, so that this layer would be surrounded by a sheath of knitting, closed on each side by threads worked on both rows of needles, while the threads supporting the threads in the middle part would b'e worked on only one row. In this cese the protective border would be made by using for the operation stronger threads than in the middle part. ln this case also the glu-- ing should be done at the same time 'the manufacture of the sheath, allowing the hot glue to run along the layer of threads on its two faces between the rows of needles.

Having thus described my invention and thebest 'means'we know of carrying the same into practical effect, l claim i An inextensble[transmission belt comprising a single layer of"'th1-eads of liber, the threads being laid closely together side by. side in Contact with one another7 said layer of threads forming the body, and the tensile member, of the belt, a layer of fabric to which saidrthreads are fastened to retain them in position, and a surface layer of knittedsfabrics. n witness whereof, l I have hereunto signed my name in the presence of two subscribing witnesses.

MAURICE LEBLANC.

Witnesses:

JULES ARMENGAUD, Jeune, LUCIEN ,MEMMINGER 

